The present invention relates to countermeasures to radar detection of exoatmospheric objects, such as aircraft or missles in flight, and more particularly, it relates to countermeasures for exoatmospheric deployment of chaff.
Countermeasures to confuse radar detection warning systems have long been in use. One countermeasure technique has been the deploying of dipoles in a cloud. Difficulty has been encountered, however, in extending the cloud of dipoles concept to exoatmospheric missile system because there is no gravity or air to aid deployment. Techniques for exoatmospheric dipole deployment have included the use of low vapor pressure liquids and solids to dispense rod dipoles. This resulted in high cloud growth rates. The weight of the chaff to produce a chaff cloud sufficient to confuse a radar is proportional to the growth rate cubed. The "growth rate" refers to the velocity at which the dipoles leave the dispensing center. Thus, the high growth rates lead to very heavy systems.
Another technique for exoatmospheric dipole deployment involves the use of a foil coil which uses thin foil dipoles. The dipoles are wound around a coiling ring by placing the tip of one under the tail of the adjacent one. This dispersion technique relies upon the spring energy in the foil dipoles. Such a chaff has lower growth rates. This type of dipole depolyment scheme has heretofore been in general use in missile countermeasures.